Lock nut



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Patented Mar. 7 23, 1943 LOCK NUT William A. Bcdi'ord, Jr., l-lingham, Mass, assignor to United-Carr Fastener Corporation, Cambridge, Mass., a corporation of Massachusetts Application June 14, 1941, Serial No. 398,090

4 Claims.

The present invention relates to improvements in self-locking wing nuts for threaded fastening installations and aims generally to improve existing devices of this kind.

In the accompanying drawing I have illustrated a preferred form of my invention which is simple of construction, economical of manufacture and efilcient for its intended purpose.

Referring to the drawing Fig. 1 is a sectional view of a typical threaded installation employing my invention;

Fig. 2 is a side elevation of a wing nut constructed in accordance with the invention;

'Fig. 3 is an end view thereof;

Fig. 4 is a bottom plan thereof;

Fig. 5 is an enlarged transverse vertical section as taken on the line 5 5 of Fig. 2;

Figs. 6, 7 and 8 are diagrammatic views illustrating steps of the method of making the wing nut.

The wing nut of the present invention is intended for use with threaded fastenings, such as a screw or bolt, having a head 2 and a threaded shank 3, which may be passed through apertures in a plurality of plates 4-5. and receive the wing nut 6, whereby the plates may be clamped between the head 2 and nut 6.

According to the invention, the wing nut may be formed from a single blank ID of generally circular or slightly elongated circular sheet metal disc. An integral tubular shank II is then drawn from the blank to form a bolt or screw-receiving shank. Thereafter side portions l2 of the disk on opposite sides of the shank are bent towards each other to form a base l3 in a plane normal to the axis of.the sheet, the folded Wings forming a handle portion adapted to be engaged by the user in turning the nut.

In bending the wings or side portions I! together, they are formed around a mandrel I5 of slightly less diameter than the bore of the shank II, and poistionedaxially of the shank. Portions of the wings on opposite sides of the mandrel are pinched together into contactwith each other, as at l6, thus forming, in said wings, an elliptical bolt or screw-receiving bore or passage H, the minimum diameter of which is less than the internal diameter of the shank I I, or the diameter of the screw.

The bore of the shank II and the inner face of the wings along the minimum diameter of the passage ii are then threaded as by a usual tapping operation, and as the minimum diameter of the passage I1 is less than the bore of the shank templated.

I l, the root diameter of the threaded passage will be less than the outside diameter of the screw.

In practice, the wing nut 6 may be easily threaded upon the'shank 3 of the screw, until the end of the screw enters threaded passage I! in the wings l2. The minimum diameter of the passage I! being less than the diameter of the screw shank 3, there is a resistance to threading the passage l1 over the screw shank. However, the wings I2, being of sheet metal and integrally formed with the base l3 are yieldable to a sufficient degree to permit slight separation thereof, allowing the passage H to be threaded upon the shank 3.

The wings l2, however, possess sufllcient stiifness so as to exact a considerable tension or drag upon the screw shank 3 so that considerable force is required to effect a complete threading of the shank H and passage ll upon the screw shank 3. This effectively resists accidental unthreading of the wing nut, after it has once been threaded to clamping position.

While it is desirable that the side portions of the wings along the minimum diameter of the passage ll be threaded, as above described, conceivably these maybe omitted in certain cheap and inexpensive installations where repeated removal of the wing nut from the screw is not con- In such case the inner side of the wings l2, along the minimum diameter of the passage exact a drag or braking effect against the sides of the screw.

My invention is not to be interpreted narrowly as limited to the specific forms and constructions shown and described. which are intended merely as illustrative, but includes as well equivalent constructions and steps as may fall within the scope of the appended claims.

I claim: I

1. A wing nut formed from a flat strip of sheet metal comprising a base having a screw-receiving opening and elements adjacent said opening for threaded engagement with said screw, resilient wings integral with opposed side edges of said base extending outwardly from said base, said wings having their inner broad surfaces in opposed facing relation and portions of said wings combining to form finger-gripping elements, and portions of said wings being cupped and threaded and constituting a yieldable threaded screw-receiving passage in substantial alignment with said screw-receiving opening.

2. A wing nut formed from a fiat strip of sheet metal comprising a base having a screw-receiving opening and elements adjacent said opening for threaded engagement with said screw, resilient wings integral with opposed side edges 0! said base extending outwardly from said base, said wings having their inner broad surfaces in opposed racing relation and portions of said wings abutting at their outer edges to form fingergripping elements, and said wings having por tions intermediate said abutting portions cooperating to form a yieldable screw-receiving passage in substantial alignment with said screwreceiving opening.

3. A wing nut formed from a flat strip of sheet metal comprising a base having a screw-receiving opening and elements adjacent said opening for threaded engagement with said screw, resilient wings integral with opposed side edges of said base extending outwardly from said base, said wings having their inner broad surfaces in opposed facing relation and portions of said wings abutting at their outer edges to form fingergripping elements, and portions of said wings intermediate said abutting portions being cupped and threaded and constituting a yieldable threaded screw-receiving passage in substantial alignment with said screw-receiving opening.

4. A wing nut formed from a flat strip of sheet metal comprising a flat base, resilient wings integral with opposed side edges oi! said base extending outwardly from said base, a tubular threaded shank formed from said base and disposed between said wings, portions of theoutermost edges of said wings being cupped and threaded and constituting a yieldable threaded screw-receiving passage in alignment with said tubular shank, and portions of said edges abutting laterally of said cupped portions on opposite sides thereof to form finger-gripping elements.

- WILLIAM A. BEDFORD, JR. 

